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LS engine or Big Blocks

JYef399

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Just curious are guys out there running LS engines and getting good performance out of them ? Seems like you can get a lot of power out of an LS pretty cheap. Or is there a reason why big blocks are just industry standard ?
 

sintax

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I have not check on Marine gear for an LS but would assume its pricey and not as easy to pick up...
more and more is showing up. Some factory boats (mostly wake) are using LS platforms now, but the parts are not exactly performance. I think where things get interesting is when you start talking about 427 ci+++ LS's. It seems that might be the sweet spot between displacement and performance. Theres no question that the drag race guys have built some monster single turbo LS cars.
 

HighVoltage329

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Light weight boats with light weight high rev LS engines is where I think there's a good match. Hardin marine is making/selling some nice exhaust including turbo headers.
 

Qwiketz

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probably a good question for tahiti boats since they have equipped several of their builds with ls based engines both with outdrive and jets.
 

02HoWaRd26

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probably a good question for tahiti boats since they have equipped several of their builds with ls based engines both with outdrive and jets.
That’s just a factory setup with the LSA tho, not a custom build.

I’ve spoken in great detail with the builder for my offroad car engine and he says cast block 408/416” depending on the block and small turbos would be a perfect swap and make a very conservative 700-750hp with the same or better tq curve. Than you start at Hardin Marine with all the accessories etc and realize its all there and just awaiting someone to do it and wake up the masses.
 
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rivermobster

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Just curious are guys out there running LS engines and getting good performance out of them ? Seems like you can get a lot of power out of an LS pretty cheap. Or is there a reason why big blocks are just industry standard ?
HP is one thing, torque is another.

I can't imagine a an LS would push a jet very well.

But, if you came up with some interesting gearing and propage (I just made that word up!), maybe an LS could work?

A deep pocket book would be required for testing I'm thinking...
 

Qwiketz

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That’s just a factory setup with the LSA tho, not a custom build.

I’ve spoken in great detail with the builder for my offroad car engine and he says cast block 408/416” depending on the block and small turbos would be a perfect swap and make a very conservative 700-750hp with the same or better tq curve. Than you start at Hardin Marine with all the accessories etc and realize its all there and just awaiting someone to do it and wake up the masses.
True. I can’t remember if it was them or someone else that picked up a ls454 from Kodac. I think that might be a decent barometer as to how these ls engines handle the constant duty

 

02HoWaRd26

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HP is one thing, torque is another.

I can't imagine a an LS would push a jet very well.

But, if you came up with some interesting gearing and propage (I just made that word up!), maybe an LS could work?

A deep pocket book would be required for testing I'm thinking...
Properly built you’ll see an LS-X build makes insane tq. 440” with a 4.5L which now you’re talking $$$ will make a solid 1200hp and 980-1050tq and still make a tq curve that starts getting after it in the low 2000rpm range but doesn’t drop off till into the 5000’s yet spin 6800-7100rpm all day long.
 

rivermobster

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Properly built you’ll see an LS-X build makes insane tq. 440” with a 4.5L which now you’re talking $$$ will make a solid 1200hp and 980-1050tq and still make a tq curve that starts getting after it in the low 2000rpm range but doesn’t drop off till into the 5000’s yet spin 6800-7100rpm all day long.
How much did you say that cost you exactly?
 

rivermobster

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Not me...... and i did say you’d be talking $$$$$$ but A: it’s going to be lighter and B: it’d be cool and different.
10-4. You have a link to this build? That's a lot of torque from a small displacement engine!
 

02HoWaRd26

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10-4. You have a link to this build? That's a lot of torque from a small displacement engine!
418” 750hp/725tq

454” 900hp 875tq

463” 1600hp 1400tq


And this is just CBM there are plenty of others doing similar and bigger platforms. Mike Porter of Redline has moved the LS bar up from there as well.
 

MK1MOD0

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Those CBM motors are sweet. 750hp in an all aluminum package! Very cool.
 

rivermobster

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418” 750hp/725tq

454” 900hp 875tq

463” 1600hp 1400tq


And this is just CBM there are plenty of others doing similar and bigger platforms. Mike Porter of Redline has moved the LS bar up from there as well.
Bruce is a friend of mine...

You realize not one of those engines are rated at 1000ft lb of torque, correct?
 

02HoWaRd26

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Bruce is a friend of mine...

You realize not one of those engines are rated at 1000ft lb of torque, correct?
Well except the one that clearly states 1400tq. The numbers i gave earlier are a 440 a good buddy just built for his sand car. When I’ve spoke with Bruce, he’s told me straight out he could build, or more more correctly Brent could build me more than plenty. Idk what dick sizing contest you’re trying to swing but you asked for a link i posted it. As well there is Danzio, Redline, TSP, Alper, Mast and many others who are all making these same numbers day in day out from an LS. And no one said “LS1” biggest I’ve seen so far myself was 489” from an LS platform and have heard in excess of 500”.
 
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farmo83

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Alexi at Boostpower basically described it as a supply and demand issue. Not many folks in the performance boat market are looking for LS stuff so most of the builders aren't doing custom stuff for them.
 

Blackmagic94

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That’s neat that people are making bigger hp with ls motors with forged induction but you aren’t seeing as much hp from a NA LSx as you will a bbc


I mean it’s pretty easy to build a 600-700 hp large cube bbc like the 548s in my cig as a pump gas engine. Try doing that with an LSx

Bbc is still the king of big power after the hemi headed nitromethane motors.

look at a billet proline motor making 4500 hp
 

MK1MOD0

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I don’t think anyone is saying a LS will make the same NA HP as a 623 CI BB. We all know there is no replacement for displacement. But seriously, how many boaters are looking for 1200 HP and up ? A very tiny percentage. The LS package provides a great option for those looking for good HP in a smaller, liter package. Hell, my wife’s new wake boat is I believe 450hp in an LS motor. Mercury never even offered a 496 in that power range. So no doubt an LS it’s available, and reliable. It’s just more more option for the boating community, and I LIKE options.
 
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rivermobster

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Well except the one that clearly states 1400tq. The numbers i gave earlier are a 440 a good buddy just built for his sand car. When I’ve spoke with Bruce, he’s told me straight out he could build, or more more correctly Brent could build me more than plenty. Idk what dick sizing contest you’re trying to swing but you asked for a link i posted it. As well there is Danzio, Redline, TSP, Alper, Mast and many others who are all making these same numbers day in day out from an LS. And no one said “LS1” biggest I’ve seen so far myself was 489” from an LS platform and have heard in excess of 500”.
LoL...

No contest at all. Just asking where you got your info!

Clearly, with enough money, you can build what ever you want.

I took the OP's question, with the objective of being inexpensive, since he used the word "cheap" in his initial question.

Like how the street rodders do it?

Stock 5.3 with a mild tune works Great in a 60's car or truck, and is probably less expensive and more power than a performance SBC rebuild. Right? Including the complete 5.3 powertrain!

Now could you do something like that in a boat??

That's the question I think he wants answered. To me, the answer is no.

Cool? Yes.

Different? Yes.

Cost equivalent? Probably not.

BBC has been the industry standard cause you get a whole lot of torque on the "cheap".
 
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The insane thing about the LS platform is the obscene strength of the OEM rotating assembly. It's a fully skirted block. The mains dont move at all. 1000-1200 hp out of 5.3 truck engines with Ebay/Amazon turbo setups happen quite literally, every day. The 6.0 and 6.2 blocks dont take boost as well, but are still capable of staying together at 1000hp and 900ft lbs of torque, all day. With Cast pistons, powdered metal rods and the OEM cast crank. It's absurd. But it all comes from that fully skirted block.

I've wondered why there isn't a flat bottom class that runs that 5.3 LM7 that can literally be had for $1000 complete. Limit it to an 850 CFM carb and .485 lift and you've got an entry class combo that every jug head on the planet can assemble for next to nothing and go racing with it for 5 seasons probably. Wanna see 20 boat fields again? Start there.

But the King of HP and Torque, the BBC. No question. I just bolted one together that made over 750hp on a single carb at only 501ci.
 

rivermobster

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Everyone is following Finnigan's build, right?


Mid 70's. But I'm not sure what engine it is?

 

Racey

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Well except the one that clearly states 1400tq. The numbers i gave earlier are a 440 a good buddy just built for his sand car. When I’ve spoke with Bruce, he’s told me straight out he could build, or more more correctly Brent could build me more than plenty. Idk what dick sizing contest you’re trying to swing but you asked for a link i posted it. As well there is Danzio, Redline, TSP, Alper, Mast and many others who are all making these same numbers day in day out from an LS. And no one said “LS1” biggest I’ve seen so far myself was 489” from an LS platform and have heard in excess of 500”.
The bigger question is 1,400 ft/lbs on who's dyno.... 🤣

You can't hold or measure that kind of torque on a SuperFlow. You need something like Brummett has to get a real measurement when you start breaking through the 1100ftlb arena. It quickly becomes sobering when you put someone else's motors HP/TQ claims on his dyno :p. All of a sudden things make more sense.
 
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Everyone is following Finnigan's build, right?


Mid 70's. But I'm not sure what engine it is?

That was a worn out 6.0 I'm pretty sure. They used that same boat in another episode where they pulled the LS engine out of the "muscle truck" in the parking lot of the boat ramp, put it in the boat, did a lap around Elsinore and then put it back into the muscle truck. I saw that and it was funny. RoadKill at it's finest.

Finnegan was braver than smart that day. He's lucky it broke when it did. Had it tossed that rod going through the lights at 100mph, it wouldn't have been pretty.
 

Goodtime$

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Ok we do a lot of LSA in a DECKBOAT jet which no bullshit is the most load a motor will go under to get that pig up and flying.

LSX 454 should be the best choice as of today based on torque specs solely and value.
6.0L iron block w power added second for garage tech pros.

1. the issue with the LS motor is closed cooling will keep it alive and can be complex and ugly

2. they make power, but they run up through the RPMs so fast it’s hard to tune an impeller for them

my 2 cents
 

Uncle Dave

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That’s just a factory setup with the LSA tho, not a custom build.

I’ve spoken in great detail with the builder for my offroad car engine and he says cast block 408/416” depending on the block and small turbos would be a perfect swap and make a very conservative 700-750hp with the same or better tq curve. Than you start at Hardin Marine with all the accessories etc and realize its all there and just awaiting someone to do it and wake up the masses.

Sure it could, but who has done an LS turbo with a closed hatch outdrive boat ?
The single turbo LA manifold alone from hardin is 4K alone and you still have to buy the other side.
 

Uncle Dave

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418” 750hp/725tq

454” 900hp 875tq

463” 1600hp 1400tq


And this is just CBM there are plenty of others doing similar and bigger platforms. Mike Porter of Redline has moved the LS bar up from there as well.
Blown small blocks been around forever, I did my share of these in the 90's - how many of these are intercooled?

I prefer to pay for cubes vs windmills. I dont want the plumbing and associated complexity.

What does CBM mean by this?
All CBM Motorsports Marine engines and accessories are not marinized.
 

02HoWaRd26

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Sure it could, but who has done an LS turbo with a closed hatch outdrive boat ?
The single turbo LA manifold alone from hardin is 4K alone and you still have to buy the other side.
Why do a single, I’d do small twins. And sure you can intercooler anything. Idk the op asked about it, and i did a ton of homework when planning to do my last boat. Things changed when we bought our new to us boat but it’s still completely do able, and about 13k for everything other than the long block.

Some seem to just try and turn every thread into a place to argue tho.
 

n2otoofast4u

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B Is For Build on YouTube is putting Texas Speed LSX Motor’s in his Italian yacht thing. He local to me, I’m looking forward to the end results.
 

QC22

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I'm looking to repower my 270 (heavy) this off-season and I'd consider an LS based engine in a heartbeat if I could find one., The Ilmor MV8 570 (454 cubes) has been on my list, but I think Ilmor has pretty much dropped out of the performance market. As far as torque is concerned this is always misunderstood in marine applications. If it will plane, you don't care, if it won't, you do. My 270 with a 496 HO will plane at 2000 RPM by slowly ramping up the throttle. What kind of torque do you think that is? Next to nothing. Propeller load "curves" are linear. You literally NEVER see peak torque in a marine application unless the throttle is hammered 100%. 100+ MPH boats are an exception in that they have to be propped so high that the initial jump onto plane is a very steep load. But any one of you take out your boat and slowly ramp the throttle up 100 RPM at a time. If it planes before 100% mashed, peak torque was not in play.
 

Robert Mason

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I am pulling the LSA indmar package out of my 21 skirt from Tahiti and building a 416ci ls with 4.0l whipple. Just so you know the skirt with the LSA and a dominator went 68 mph top speed. The LSA has 27 hrs on it and will be for sale soon. Full package with all accessories, closed loop cooling, exhaust etc.
3F00DD23-5483-4B7F-BEBB-9B66804368B4.jpeg
 

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pronstar

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You can make over 1,000 go on a 5.3L LS with turbos.

But there’s a reason why Merc went with a 9L engine for their 1000+ ho boat motors.

Specific output - power per given displacement - is a thing as far as longevity is concerned.

Big motors are good for some applications.
Small motors are good for other applications.


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